1. Field of the Invention
The present invention relates to an ink jet printing apparatus, an ink jet printing method, and an image processing apparatus.
2. Description of the Related Art
In a serial type ink jet printing apparatus, a printing scan in which a printing head is moved while causing the printing head to eject ink in accordance with image data and a conveyance operation to convey a printing medium in a direction intersecting the direction of the printing scan are repeated alternately. At this time, there is a case where a joint streak occurs at the boundary part between the regions in which printing is performed by printing scans performed twice successively in the printing medium.
For example, Japanese Patent Laid-Open No. 2002-36524 has disclosed the apparatus that counts the number of dots that are printed in the vicinity of the boundary part and adjusts the thinning ratio at the boundary part in accordance with the number of counted dots. How a joint streak is conspicuous depends on the number of gradations, i.e., the number of dots that are printed but by adopting Japanese Patent Laid-Open No. 2002-36524, it is possible to appropriately adjust the number of dots at the boundary part in accordance with the number of gradations, and therefore, it is made possible to make less conspicuous the joint streak regardless of the density.
However, in the case where the thinning ratio at the boundary part is adjusted in accordance with the gradation as in Japanese Patent Laid-Open No. 2002-36524, the dot arrangement state at the joint part is different from the dot arrangement state in the other region, and therefore, there has been such a case where the texture or the feeling of granularity inherent in the joint part occur and the joint streak is made more conspicuous on the contrary.